Wednesday, April 1, 2009

Scientists Find Safer Way to Make Human Stem Cells

There was a new breakthrough that was reported on March 26, 2009 with details about a new way to make an embryonic stem cell from a skin cell without having to use viruses. The article state that they made induced pluripotent stem cells (iPS cells) so that there was not any genetic material left being to pose risks. They are trying to find many different ways to make the skin cells behave like embryonic stem cells so that they can create new treatments without the ethical controversies. Previously, they were using a vector to carry genes into the cell and cause the cell to reprogram itself. Jame Thomson from the University of Wisconsin said that the new method involved using a plasmid, circle DNA, to carry the genes needed for reprogramming. Furthermore, he said that the plasmids disappear over time so that the harmful genes can not be placed into the cell's DNA through recombination; thus, less or even no tumor formation. Thomson believes that there will be many ways to produce iPS cells and they will start to look at which method produces the most consistent results. (The article can be found at: http://www.newsdaily.com/stories/tre52p5wr-us-stemcells-safety/ )

If this method becomes possible it will diminish most of the debate regarding the use of stem cells because they will not need to "kill" an embryo. However, there are some drawbacks to this method. According to Jerome Zack PhD., the length of time to transform the cells into iPS cells is a couple of months. Therefore, if a patient suffers a heart attack and needs a new heart immediately they they would not be able to grow a heart fast enough for him to survive using iPS cells. He stated that the cost of reprogramming cells is relatively high. Additionally, he mentioned the possibility of the cells to produce cancer; however, the video was released prior to this new method described above so that may or may not be te case with the new plasmid method. (The video can be found at: http://www.youtube.com/watch?v=iTIhv4l7qPs )

I believe that this method could decrease the debate dramatically; however, I think that embryonic stem cells will still need to be used in some cases. As Zack described, the advantage of embryonic stem cells over iPS cells is that they can be readily available and can be used immediately. Therefore, if a patient had a heart attack and needed a heart they could use a embryo that was ready to go and produce a heart for him. I think that if the scientists are able to produce the iPS cells without causing cancer then they should use that method to create the organs that are not needed immediately instead of the embryonic stem cells in order to help diminish the debate. However, if the unfortunate case arises and doctors need an organ immediately to save a patients life then I think that they should be able to use the embryonic stem cells to save his life. His life is very important and should not be lost because scientists were forbidden to make an organ for him.

Above is a diagram of how the induced pluripotent cells are created using the skin cells of a mouse. This method uses retroviruses to inject the specific genes in to the cell. These genes are known as the master regulators that keep the cells in the embryonic stem cell-like state. Next, the scientist used specific methods to differentiate the cells in to blood stream cells and they were injected in to the sickle-cell anemia mouse.

2 comments:

I think you’re very fair to bring up the fact that even with iPS there are certain setbacks like in the case of a patient who needs a heart transplant immediately. However, who knows, the first time they created an iPS cell was in 2007, now two years later they have already worked through some of the setbacks and by 2011 who knows perhaps they may have found a solution to that as well. The most important thing is that we need to continue the research and have fewer setbacks.

This looks to be like a great alternative to use instead of actual embryonic stem cells and I agree would decrease the controversy. If they could get regular skin cells and manipulate them to act like an embryonic stem cell, then actual patients can probably just use their own skin cells and there wouldn't be the case of rejecting it since it came from your body and not someone random. Taking away the cancer risk too helps me favor the use of iPS cells over embryonic, but again I still think that embryonic can also be useful. I wonder if this new research will lead away from doing research using embryonic, and instead just focus on perfecting the iPS cells.